THE POISON GARDEN website

Pontifications on Poison

Being some ramblings on events associated with poisonous plants.

Tuesday 28th June 2011

Isn’t nature wonderful?
Last week, I mentioned that my
Verbascum x hybrida ‘Southern Charm’ had blown over in the
wind. This was before the full flower spike had opened. Like
many other plants, the flowers on the Southern Charm open from
the bottom of the spike upwards. I regretted that I hadn’t got
around to staking the plants as the flowers are amongst my
favourites.

But, just a week later, as the picture shows, the top third
of the flower spike has turned itself back to the vertical and
looks stunning. I say ‘like many other plants’ but, it appears
that this is not common to the whole Verbascum genus because the
flowers on the two olympicums that have seeded themselves in the
front garden seem to be opening at random on the spike.

It’s another example of a plant getting on and doing its job
which is to flower, get itself pollinated and reproduce. The
pull to reach up to the light as part of this process is
amazingly strong. I remember seeing a tree, a few years ago when
I was out walking, that had, at some early point in its life
been blown over. It efforts to grow straight had been frustrated
by some large rocks just next to it and, as result, the trunk
had completed a full circle before finding itself in a position
to grow straight and tall. I should try and find it and get some
pictures.

But the best example of how keen plants are to reproduce was
in the Poison Garden at Alnwick in the first full year. The
layout of the Poison Garden included a number of steel cages.
The purpose of these was something like five parts
architectural, five parts for the PR value of saying that the
garden had plants that were so dangerous they had to kept
caged, and one part because visitor contact with the particular
plants needed to be avoided.

That lower priority on function meant that no consideration
was given to the needs of the plants to be grown in the cages.
The cages were heavy steel frames with mesh sides and no means
of access to undertake any work on the plant within. Plus, the
cages were of a uniform 2m height regardless of the growing
habit of the plants.

In the second year of the Poison Garden, 2006, the gardeners
planted three
Heracleum mantegazzianum, giant hogweed, close together, and
covered them with a cage. Now, even professional gardeners
cannot be expected to know how to grow a plant like giant
hogweed so the Alnwick Garden staff can be forgiven for not
realising that all three plants would flourish and that, within
a couple of months of planting they would completely fill the
cage.

In fact, by June, as the picture shows, the flowers of the
plants were pressing so hard against the cage that visitors were
genuinely concerned that they might be about to burst through
and fire toxic material all around. So, it was decided to remove
the flower heads. Because of the nature of the plant and the
design of the cage, that relatively simple task required six
gardeners in full protective clothing and facemasks so that no
skin was exposed.

The idea was for four people to lift the cage up enabling the
other two to remove the flower heads. Unfortunately, the three
plants growing so close together were exerting outward pressure
on each other so that, when the cage was removed, all three
splayed outwards. It was immediately obvious that it would be
impossible to stand the plants up and replace the cage so the
plants were cut off about a metre from the ground and the cage
put back in position.

Within a month new flower heads had formed on the plants
without reproducing the tall stalks normally associated. To the
right of the picture of this second flowering you can see the
cut off stalk from the first growth. Though much smaller and
showing no tendency to burst out of the cage, it was decided to
remove these flower heads to prevent them seeding. This was a
much simpler operation though still requiring quite a bit of
muscle to tilt the cage to allow access.

Remarkably, within three weeks the plants had again flowered,
this time on stalks that were no more than 25cm in height.

Talking of flowering, my poppies are just beginning to show
off their wonderful colours. The very definition of a
‘Lethal Lovely’.